Extended Data Fig. 1: Tip-sample distance dependence of the scattered transients for the first and third harmonic.
From: All-optical subcycle microscopy on atomic length scales
First (a) and third (b) harmonic, \({E}_{1}^{{\rm{scat}}}\) and \({E}_{3}^{{\rm{scat}}}\), of the scattered electric fields, measured simultaneously with the transients shown in Fig. 1b (peak far-field strength \({\hat{E}}_{{\rm{light}}}=1.3\) kV cm−1). For the closest tip-sample distance about 900 electrons are rectified per pulse on average. The colours correspond to the distances shown in Fig. 1c. The strong underlying nonlinearity is highlighted by the increased difference in signal strength for different tip-sample separations when going to higher demodulation orders.
